5.4.99.64	(R)-3-hydroxybutanoyl-CoA	poor substrate	Aquincola tertiaricarbonis	2-hydroxy-2-methylpropanoyl-CoA	-	r	434952	
5.4.99.64	(R)-3-hydroxybutanoyl-CoA	2-hydroxy-2-methylpropanoyl i.e. 2-hydroxyisobutanoyl-CoA. 2-Hydroxyisobutanoyl-CoA is predominantly converted to (S)-3-hydroxybutanoyl-CoA, and only minor amounts of about 20% of the (R)-enantiomer are obtained	Aquincola tertiaricarbonis	2-hydroxy-2-methylpropanoyl-CoA	-	r	434952	
5.4.99.64	(R)-3-hydroxybutanoyl-CoA	very low activity with wild-type enzyme. Mutations D117V or D117A in the large subunit HcmA result in significantly increased activity toward (R)-3-hydroxybutyryl-CoA	Aquincola tertiaricarbonis	2-hydroxy-2-methylpropanoyl-CoA	-	r	434952	
5.4.99.64	(R)-3-hydroxybutanoyl-CoA	2-hydroxy-2-methylpropanoyl i.e. 2-hydroxyisobutanoyl-CoA. 2-Hydroxyisobutanoyl-CoA is predominantly converted to (S)-3-hydroxybutanoyl-CoA, and only minor amounts of about 20% of the (R)-enantiomer are obtained	Aquincola tertiaricarbonis L108	2-hydroxy-2-methylpropanoyl-CoA	-	r	434952	
5.4.99.64	(R)-3-hydroxybutanoyl-CoA	catalytic efficiency for the (R)-enantiomer is about 11 times higher than for the (S)-enantiomer	Kyrpidia tusciae DSM 2912	2-hydroxybutanoyl-CoA	-	r	436656	
5.4.99.64	(S)-3-hydroxybutanoyl-CoA	-	Aquincola tertiaricarbonis	2-hydroxy-2-methylpropanoyl-CoA	-	r	434960	
5.4.99.64	(S)-3-hydroxybutanoyl-CoA	favorite substrate	Aquincola tertiaricarbonis	2-hydroxy-2-methylpropanoyl-CoA	-	r	434960	
5.4.99.64	(S)-3-hydroxybutanoyl-CoA	-	Aquincola tertiaricarbonis L108	2-hydroxy-2-methylpropanoyl-CoA	-	r	434960	
5.4.99.64	(S)-3-hydroxybutanoyl-CoA	catalytic efficiency for the (R)-enantiomer is about 11 times higher than for the (S)-enantiomer	Kyrpidia tusciae DSM 2912	2-hydroxybutanoyl-CoA	-	r	436672	
5.4.99.64	2,2-dimethylpropanoyl-CoA	wild-type enzyme as well as I90V (HcmA) and I90A (HcmA) mutant enzymes can also isomerize pivaloyl-CoA and isovaleryl-CoA, albeit at more than 10times lower rates than the favorite substrate (S)-3-hydroxybutyryl-CoA	Aquincola tertiaricarbonis	?	-	r	436738